fix(ingress/nginx_gateway_fabric_legacy): default control-plane min_replicas to 1

Align the legacy aws/azure/gcp NGF ingress modules with the utility module:
control-plane autoscaling min_replicas default 2 -> 1 (schema default + sample
spec). A single steady-state control plane avoids the multi-replica
config-divergence behind the intermittent 502s; HPA still scales up under load.
Data-plane scaling unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 2 people

modules/ingress/nginx_gateway_fabric_legacy_aws/1.0/facets.yaml

@@ -176,7 +176,7 @@ spec:
               type: integer
               title: Minimum Replicas
               description: Minimum number of controller pods (HPA lower bound)
-              default: 2
+              default: 1
             max_replicas:
               type: integer
               title: Maximum Replicas
@@ -946,7 +946,7 @@ sample:
           memory: 512Mi
     control_plane:
       scaling:
-        min_replicas: 2
+        min_replicas: 1
         max_replicas: 3
         target_cpu_utilization_percentage: 70
         target_memory_utilization_percentage: 80

modules/ingress/nginx_gateway_fabric_legacy_azure/1.0/facets.yaml

@@ -173,7 +173,7 @@ spec:
               type: integer
               title: Minimum Replicas
               description: Minimum number of controller pods (HPA lower bound)
-              default: 2
+              default: 1
             max_replicas:
               type: integer
               title: Maximum Replicas
@@ -943,7 +943,7 @@ sample:
           memory: 512Mi
     control_plane:
       scaling:
-        min_replicas: 2
+        min_replicas: 1
         max_replicas: 3
         target_cpu_utilization_percentage: 70
         target_memory_utilization_percentage: 80

modules/ingress/nginx_gateway_fabric_legacy_gcp/1.0/facets.yaml

@@ -173,7 +173,7 @@ spec:
               type: integer
               title: Minimum Replicas
               description: Minimum number of controller pods (HPA lower bound)
-              default: 2
+              default: 1
             max_replicas:
               type: integer
               title: Maximum Replicas
@@ -943,7 +943,7 @@ sample:
           memory: 512Mi
     control_plane:
       scaling:
-        min_replicas: 2
+        min_replicas: 1
         max_replicas: 3
         target_cpu_utilization_percentage: 70
         target_memory_utilization_percentage: 80